drm/radeon/dpm: Convert to use devm_hwmon_register_with_groups

Simplify the code and fix race condition seen because
attribute files were created after hwmon device registration.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 file changed